This is basically an interface extracted from Texture without any knowledge
about any actual implementation, except for copyRectToTexture, fill, and
dirty rect handling. These are convenient helpers.
This mode should *not* be used by any new engines/code. If someone is going
to use it and says it works with the OpenGL output, please make them wear a
red uniform and beam them onto a remote planet.
Formerly, we required that the OpenGL mode was fixed at compile time. Now we
allow the code to work with whatever it is given at runtime.
It is still possible to force a context type on compile time.
This used to be used by Sword25. Since it is not supported by GLES and no
engine code uses it we drop support. Hopefully, this helps people to realize
they should not use that format in their engine.
Formerly we relied on static linkage. However, in the presense of modern
OpenGL (ES) implementations it is not easily identifable which library to link
against. For example, on Linux amd64 with nVidia drivers and SDL2 setup to
create a GLES 1.1 context one would need to link against libGL.so. However,
traditionally GLES 1.1 required to link against libGLESv1_CM.so. To prevent a
huge mess we simply resolve the OpenGL functions on run-time now and stop
linking against a static library (in most cases).
GLES support needs to be enabled manually on configure time for now.
Tizen changes have NOT been tested.
Bug is: "IRIX: X BadMatch when trying to start any 640x480 game".
40e019efd4 introduced resetting the pixel depth
when unloading modes for SDL output. This was required to make mode listing
for OpenGL work on Win8+.
This causes issues on non-Win32 platforms though. SDL might not give us a valid
a pixel depth, causing the resetting to fail. A particular example is X11 on
IRIX, when only 16bit output modes work. Initially SDL tells us that the pixel
depth is 32bit. Trying to set this up causes a crash though.
Since there is no way to validate SDL's return value, we simply limit the reset
to platforms where it is actually required, i.e. Win32.
This gets rid of the feeling of the mouse sticking to black borders by using
the full output resolution as area for tracking game mouse movement. The same
behavior is present in plain SDL output with SDL2.
Formerly we did not initialize the mouse emulation from SdlEventSource
properly. Now hopefully joysticks etc. should work fine with the SDL OpenGL
output too.
Subclasses of OpenGLGraphicsManager are now supposed to supply a refreshScreen
function which handles actual screen updating (for example, buffer swapping).
As a side effect we get better coordinates from mouse move events in
fullscreen, i.e. we do not get actual window coordinates but something close
to actual viewport coordinates. The easily noticable issue is that mouse
coordinates inside black bars are outside of the viewport. For example, the
x coordinate can get negative when there's a black bar at the left side.
